USPSYCH: Insomnia May Signal More Mental Health Disorders to Come

NEW ORLEANS, Nov. 20 -- The pathology behind insomnia may be a more than a consequence of mental disorders such as depression, anxiety, and alcohol abuse, investigators here said. It may be a harbinger an underlying cause.

For example, in a study that evaluated patients with insomnia and new-onset mood disorders, insomnia preceded the mood disorder about 40% of the time, and it was concurrent with the disorder about 30% of the time, said Jeffrey M. Nard, M.D., of the Eastern Virginia Medical School in Norfolk.

Only in the remaining minority of 30% of patients did insomnia come after the mood disorder, Dr. Nard said at the U.S. Psychiatric & Mental Health Congress here.

Although anxiety often precedes insomnia-keeping patients tossing and turning at night-about 15% of those with an anxiety disorder reported having insomnia first, the same study found, Dr, Nard said.

Furthermore, in another study that followed about 1,000 randomly-selected HMO patients for three years, those with insomnia were nearly four times more likely to be newly diagnosed with major depression and nearly twice as likely to be diagnosed with an anxiety disorder, Dr. Nard said.

In another study of patients with insomnia, those whose insomnia had resolved at one year were less likely to be diagnosed with major depression than those whose insomnia persisted (0.6% versus 14%), Dr. Nard said.

In the same study, patients with resolved insomnia were less likely to be diagnosed with anxiety disorders (7.4% versus 25.6%) and alcohol abuse (2.5% versus 3.4%), Dr. Nard said.

Alcohol abuse may have an especially important tie to insomnia, Dr. Nard suggested. While the number-one non-prescription sleep aid in the United States is Tylenol PM, the number two non-prescription sleep aid is alcohol, he said.

"People will get themselves to sleep with or without our help," Dr. Nard said.

These findings suggest that patients with mood disorders should be routinely screened for insomnia. When insomnia is present, treating it simultaneously with the mood disorder may be especially beneficial, Dr. Nard said.

For example, a double-blind, placebo-controlled study of the sleep-aid Ambien (zolipidem) in patients being treated with selective serotonin reuptake inhibitors (SSRIs) for major depression found that Ambien significantly increased total sleep time compared with placebo (P